Curable compositions of an organic acid anhydride and an alkylenimine derivative



United States Patent 3,225,013 CURABLE COMPOSITIONS OF AN GRGANIC ACIDANHYDRIDE AND AN ALKYLENIMINE DERIV- ATIVE Paul Fram, Lincoln Township,Washington County, Minn., assignor to Minnesota Mining and ManufacturingCompany, St. Paul, Minn., a corporation of Delaware No Drawing.Continuation of application Ser. No. 59,833, Oct. 3, 1960. Thisapplication Oct. 12, 1964, Ser. No. 403,331

16 Claims. (Cl. 26078) This application is a continuation of US. SerialNo. 59,833, filed October 3, 1960, now abandoned.

This invention relates to a novel, essentially anhydrous compositionwhich can be cured to form useful copolymers. In one aspect thisinvention relates to a liquid composition which can be cured by heating.In still another aspect this invention refers to laminates of andfabrics impregnated with these curable resins.

Reinforced plastic laminates which can withstand exposure to highertemperatures are desired in such applications as radar domes for highspeed aircraft, missile casings and jet engine compressor blades. Epoxytype resins exhibit certain attractive properties for such applications,e.g. low shrinkage during polymerization, good mechanical, electricaland chemical resistance, good fatigue and erosion resistance, lowmoisture absorption, excellent bonding to diverse materials anddimensional stability. Unfortunately many conventional epoxy resins havethe disadvantage of low heat distortion points.

It is, therefore, an object of this invention to provide liquidcompositions which can be cured to resins having advantages over epoxyresin systems.

Another object of this invention is to provide essentially anhydrous,thermally curable compositions.

Still another object of this invention is to provide stable liquidone-part compositions which can be cured without added activators.

A further object of this invention is to provide a new and usefuladhesive and laminating resin as well as a casting resin.

Yet another object of this invention is to provide a method forpreparing the aforesaid curable compositions and the cured productsthereof.

The liquid, thermally curable and stable compositions of this inventioncomprise an essentially anhydrous admixture of an organic acid anhydrideand an alkylenimine derivative of the formula RIB/I u where Q is an-valent radical, n is at least 2 (preferably 2 or 3), N is preferablylinked to an atom having a valence of 4 or 5 (most preferably C or P),and R and R" are hydrogen or an alkyl group which is preferably a loweralkyl group having from 1 to 8, preferably from 1 to 4, carbon atoms.The bracketed radical is also re ferred to as an azirane ring oraziridinyl radical. Q may be an aliphatic, aromatic or alicyclic organicradical which does not contain an active hydrogen (except as mayhereinafter be expressly recited) but which may contain atoms other thancarbon, such as oxygen, sulfur, nitrogen, etc. Q may also be aninorganic radical, such as 1: or the organic radical 3,225,013 PatentedDec. 21, 1965 wherein Y is either O or NH, x is either 0 or 1, and R isa divalent aliphatic, aromatic or alicyclic radical which may containatoms other than carbon, e.g. oxygen, sulfur, etc. The term activehydrogen used herein is defined in terms of the well knownTschugaeff-Zerewitinoff analytical technique, e.g. note J.A.C.S., 49,2181 (1927).

The phosphorus containing alkylenimine derivatives may contain one ormore phosphorus atoms. The preferred compounds have a single phosphorusatom and are represented by the formula where X is either oxygen orsulfur, and A A and A are selected from the group consisting of anazirane ring (as above defined), a monovalent aliphatic, a monovalentaromatic, and a monovalent alicyclic organic radical, at least two ofsaid A radicals containing an azirane ring.

Among the alkylenimine derivatives containing three reactive aziranerings are the N,N',N-tris-alkylene trimesamides, particularly thetris-l-alkyl-1,2-ethylene trimesamides. Examples of this class include:N,N,N- tris-ethylene trimesamide; N,N,Ntris-2-methylethylenetrimesamide; N,N',N"-tris-2-ethylethylene trimesamide;N,N',N"-tris-2-propylethylene trimesamide; N,N,N"- tris 2 butylethylenetrimesamide; N,N',N-tris-2-isopropylethylene trimesamide;N,N,N"-tris-2,2-dimethylethylene trimesamide; N,N,N"tris-2-methyl 2ethylethylene trimesainide; N,N,N"-tris-2,2dipropylethylene trimesamide;etc. These compounds are prepared in a manner similar to thebis1,2-alkylenamides, described later.

The phosphorus containing alkylenimine derivatives contain at least twoaziridine rings and include, for example, tris(l-aziridinyl) phosphineoxide; tris(1-aziridinyl) phosphine sulfide;N,N-diethyl-N,N"-diethylenethiophosphoramide; N,N-diethylenbenzenethiophosphondiamide; N-(3-oxapentamethylene) N',Nl diethylene phosphorictriamide; N,N'-diethylene benzene phosphondiamide; N,N-diethylene ethanephosphondiamide; butyl N,N diethylenediamidophosphate; N,N-dioctyl-N,N"-diethylenephosphoric triamide; N,N,N" tris(1,ldimethylethylene)phosphoric triamide, etc.

The carbonyl containing alkylenimine derivatives which are particularlypreferred have the formula wherein Y is either oxygen or NH, 1 is 2 or3, x is either 0 or 1, R is hydrogen or a lower alkyl group (i.e. ahydrocarbon radical having from 1 to 4 carbon atoms), and R is az-valent aliphatic, aromatic or alicyclic radical. R may contain atomsother than carbon, such as oxygen and sulfur, but does not contain anactive hydrogen, i.e. a hydrogen which is active to the Zerewitinofitest (inert to Grignard reagents). When x is 0, the compound is abis-1,2-alkylenamide. When Y is oxygen and x is 1, the compound is abis-1,2-alkylene carbamate. When Y is -NH- and x is 1, the compound is abis-1,2-alkylene urea, such as 1,6-hexamethylene N,N'-diethylene urea.

Bis-1,2-alky1ene carbamates and their preparation are described in US.Serial No. 850,541, filed November 3, 1959 now US. 3,162,617. Generally,their preparation involves the reaction of a 1,2-alkylenimine in a waterphase with a solution of a chlorocarbonate of a difunctional alcohol ina water immiscible organic solvent, in the presence of an acid acceptor,at a temperature between about 5 C. and 30 C. The following Example Aillustrates the preparation.

Example A A 250 ml. three necked flask was equipped with a stirrer,thermometer, condenser and dropping funnel. To the flask was added asolution of 41.5 grams (0.3 mol) of potassium carbonate in 50 ml. ofwater, followed by 9.0 grams (0.21 mol) of ethylenimine. This mixturewas stirred and cooled to C. A solution composed of 27.5 grams (0.1 mol)of triethylene glycol bis chlorocarbonate in 100 ml. of benzene was thenadded dropwise to the flask with stirring and cooling over a period ofabout 18 minutes. The mixture was kept at 1012 C. during the additionand was allowed to Warm to room temperature after the addition had beencompleted. Stirring was continued for an additional hour. The benzenelayer was recovered, dried over a molecular sieve, filtered andevaporated to constant weight under vacuum. 28 grams of a water-whiteliquid product (which was identified N,N'-bis-1,2-ethylene (triethyleneglycol) carbamate) were obtained, corresponding to a 99% yield thereof.The refractive index (n of this product was 1.4748 and its density (dwas 1.198. Upon analysis, this product was found to contain 974% ofnitrogen and 0.1% chlorine as compared to calculated values of 9.73% and0.0% respectively. It is also soluble in a 1:1 weight ratio with water,methanol, isopropanol, methyl ethyl ketone, ethyl cellosolve, butylacetate and toluene.

Illustrative of the bis-carbamates which are useful onepart systems ofthe present invention are: N,N-bis-1,2-ethylene (1,4-butanediol)carbamate; N,N'-bis-1,2-propylene (1,4-butanediol) carbamate;N,N'-bis-1,2-butylene (1,4-butanediol) carbamate; N,N'-bis-1,2-ethylene(diethylene glycol) carbamate; N,N'-bis-1,2-butylene (diethylene glycol)carbamate; N,N'-bis-1,2-ethylene (triethylene glycol) carbamate;N,N'-bis-1,2-propylene (triethylene glycol) carbamate;N,N'-bis-l,2-butylene (triethylene glycol) carbamate;N,N-bis-1,2-ethylene (polyethylene glycol-200) carbamate;

N,N'-bis-1,2-propylene (polyethylene glycol-1000) carbamate;

N,N-bis-1,2-ethylene (polyethylene glycol-4000) carbamate;

N,N-bis-1,2-propylene (polyethylene glycol-1000) carbamate;

N,N'-bis-1,2-ethylene (polyethylene glycol-4000) carbamate;

N,N-bis-1,2-ethylene (polypropylene glycol-1025) carbamate;

N,N-bis-1,2-ethylene (polybutylene glycol-500) carbamate;

N,N'-bis-1,2-ethylene [1,1-isopropylidenebis (p-cyclohexanol)]carbamate;

N,N'-bis-1,2-ethylene [1,1'-isopropylidenebis (p-phenyleneoxy)di-2-propanol] carbamate;

N,N'-bis-1,2-ethylene phenylenoxydiocetamide;

N,N'-bis-1,2-ethylene phenylenoxy carbamate;

N,N-bis-1,2-ethylene-4,4'-bisphenyl carbamate;

N,N-bis-1,2-ethylene 1,1'-isopropylidene-bis-phenylene) carbamate;

N,N-bis-ethylene-resorcinol carbamate, etc.

The preferred aromatic carbamates are represented by the above formulawherein R is 1,3-phenylene, 1,4-phenylene, 1,1-isopropylidene-bis-phenylene, or 1,1-isopropylidene bis (p-phenylenoxy)di-2-propanol. The preferred aliphatic carbamates are represented by theabove formula wherein R is a branched or straight chain alkylene radicalhaving from about 4 to about 40, preferably from about 4 to about 20,carbon atoms.

4 Bis-1,2-alkylenamides and their preparation are described in US.Serial No. 832,152 (filed August 7;. 1959), now US. 3,115,474; SerialNo. 840,255 (filedl September 16, 1959), now US. 3,115,482; and SerialNo.. 850,330 (filed November 2, 1959), now US. 3,115,490.. Generally,their preparation involves the reaction of am alkylenimine in an aqueousphase with a solution of a: dicarboxylic acid halide in a waterimmiscible organic: solvent in the presence of an acid acceptor at atempera-: ture between about -5 C. and 30 C. Illustrative of theN,N-bis-1,2-alkylenamides in accordance with this:

invention are N,N'-bis-1,2-ethylenadiparnide;N,N-bis-ethylenpentadecyladipamide; N,N'-bis-1,2-butylenadipamide;N,N-bis-1,2-ethylenepimelamide;

N,N-bis-ethylene thipdipropionamide; N,N-bis-ethylene oxydipropionamide;N,N-bis-1,2-ethylenisosebacamide; N,N-bis-1,2-butylenisosebacarnide;N,N'-bis-1,2-ethylensebacamide; N,N'-bis-1,2-ethylensuberamide;N,N'-bis-1,2-propylensuberamide; N,N-bis-1,2-butylensuberamide;N,N'-bis-1,2-ethylenazelaamide; N,N'-bis-1,2-propylenazelaamide; tN,N'-bis-1,2-butylenazelaarnide;N,N-bis-1,2-ethylendodecanoyldicarboxylic acid amide;

N,N'-bis-1,2-ethylentetradecanoyldicarboxylic acid amide;-

The preferred aliphatic bis-1,2-alkylenamides are represented by theabove formula wherein R is a branched or straight chain alkylene radicalhaving from about 4 to about 40, preferably from about 2 to about 20,carbon atoms. The preferred aromatic bis-1,2alkylenamides arerepresented by the above formula wherein R is 1,3- phenylene,1,4-phenylene, 1,4-naphthalene, or 4,4-bisphenyl. The following ExampleB illustrates the preparation.

Example B N,N-bis-ethylene isosebacamide is prepared by the reaction ofethylenimine with isosebacoyl dichloride to pro-- duce the desiredsubstantially pure monomer, with hydrogen chloride as a by-product.Specifically, it may be:

prepared as follows: A solution of about 95.6 parts of isosebacoyldichloride prepared from isosebacic acid dissolved in 400 parts ofdiethyl ether is added dropwise with: cooling and vigorous stirring to aflask containing a solution of parts of potassium carbonate and 43 partsof ethylenimine in 800 parts of water. The temperature of the mixture ismaintained below 15 C. and the acid chloride is added at a rate ofapproximately 1 part per minute. The reaction mixture is allowed to warmgradually to room temperature, while stirring, for an additional hour.During the total reaction period, the pH of the reaction mixture hasdropped from approximately 12.5 at the beginning of the reaction toabout 8.6 at the end. The ether layer is separated, dried over solidanhydrous sodium hydroxide at C. for 1 hour, the sodium hydroxide isremoved by filtration and the ether removed from the filtrate underreduced pressure. The resulting reaction product,N,N-bis-l,Z-ethylenisosebacamide, remains as a Water-white liquid.

The acid anhydrides which are employed as one component in the liquidcurable composition of this invention are preferably compatible with thealkylenimine derivative with which they are admixed. However, variousorganic solvents, such as ethyl Cellosolve, methyl ethyl ketone, butylacetate, etc. can be incorporated into the liquid composition either toimprove compatibility or for application purposes, as will later bedescribed. The preferred acid anhydrides are those which yield at leasta dibasic organic acid upon hydrolysis. Illustrative of suitableanhydrides are maleic, chloromaleic, methyl maleic, succinic, methylsuccinic, dodecenyl succinic, octyl succinic, methylene succinic(itaconic), nadic, methyl nadic, chlorendic, tricarballylic,trimellitic, pyromellitic, phthalic, tetrahydrophthalic,tetra-bromophthalic, tetrachlorophthalic, etc.

Since the acid anhydrides which are employed as one component in thecurable composition of this invention must be compatible with thealkylenimine derivative, it is therefore essential that the admixture ofalkylenimine derivative and acid anhydride be homogeneous at theelevated cure temperature or reaction temperature, though notnecessarily at room temperature. As later described, a cure temperatureis selected which is preferably below the volatilization temperature ofthe most volatile reactive constituent, although higher curetemperatures may be employed, e.g. when an excess amount of the morevolatile constituent is provided. When organic solvents, such as ethylCellosolve, methyl ethyl ketone, butyl acetate, etc., can beincorporated into the liquid curable admixture to improve compatabilityor for certain other purposes, as mentioned earlier, such solvent can bevolatilized off during the elevated temperature cure. In all cases,however, the composition must be essentially homogeneous at the curetemperature for the production of the desired copolymer, and anon-homogeneous admixture leads chiefly to the undesirable production ofthe homopolymer of the alkylenimine derivative.

Since both the alkylenimine derivatives and acid anhydrides aresensitive to moisure and frequently to hydroxyl compounds and to activehydrogen, it is important that the respective ingredients, as well asthe final curable admixture, be essentially anhydrous to provide optimumshelf life and to prevent a premature cure. The cure time may vary froma few seconds to 5 days and longer and is dependent on such factors ascure temperature, reactivity of reactants, etc. Although stoichiometricamounts of the anhydride and the bifunctiona l alkylenimine derivativemay be employed, 30 to 50% excess or more of the alkylenimine derivativeis usually used.

In preparing the curable compositions of this invention the desiredquantities of anhydrous alkylenimine derivatives and acid anhydrides arethoroughly admixed at room temperature, producing a homogeneousadmixture or an intimate dispersion. In addition to the reactiveingredients mentioned above, other elastomers, synthetic and naturalresins, fillers (e.g. silica, carbon black, powdered metals, etc.),plasticizers and coloring agents may be included in the composition,depending on the ultimate properties desired in the cured product. Epoxyresins, for example, generally improve the Water resistance of the curedproduct. The properties can be varied considerably by utilizing one ormore of the reactants in combination or by appropriate selection ofother additives. It should be understood that the homogeneous 6admixture mentioned earlier refers to a homogeneous admixture ofreactive ingredients and does not necessarily include additives, whichmay be dispersed therein.

The liquid compositions of this invention are essentially anhydrous andstable at ordinary room temperature and are cured by heating to elevatedtemperatures, the temperature being selected to provide optimum cureproperties and to regulate the cure rate, usually from about 40 C. toabout 200 C. with curing times usually ranging from about 1 minute toabout 24 hours or more.

Such liquid compositions are particularly useful when applied to varioussurfaces as impregnating agents and laminating agents. They may beapplied to various fabrics, such as glass cloth, leather, duck andtarpaulin fabric, etc. to improve wear and abrasion properties, Waterrepellency and resistance to thermal and chemical attack. They may alsobe used to laminate such materials as glass sheets, glass cloth, metalsurfaces (e.g. aluminum, steel, etc.), wood surfaces and many others.The adhesion properties of these hard resins are particularly good.

The degree of brittleness or flexibility of the cured system can becontrolled within limits by appropriate selection of the anhydride oranhydrides and/ or the alkylenimine derivative or derivatives. Use ofvarious solubilizable anhydride polymers, such as the toluene solubleelastomeric copolymer of rubber and maleic anhydride, imparts specificproperties to the cured product. Other elastomers can be converted tosoluble anhydride rubbers and subsequently reacted with alkyleniminederivatives in similar manner. The preparation of such soluble anhydrideelastomers is illustrated in the literature, see Rubber and Chem. Tech.,vol. 19, p. 319 (1946) and vol. 20, p. 938 (1947). Liquid compatiblepolymers containing anhydride groups or solid anhydride polymers whichcan be dissolved in a mutual solvent with the alkylenimine derivativeare suitable acid anhydrides within the scope of this invention.

The cured products thereby produced are copolymers which compriserepeating monomeric units corresponding to the anhydride, e.g.

[i JR("Jo] and the alkylenamine derivative, e.g.

The copolymer product is different from that obtained by reacting thealkylenimine derivative with an organic carboxylic acid (rather than theanhydrides used herein) or by reacting the alkylenimine derivative Withan anhydride in the presence of water.

Example 1 The following anhydrous ingredients were blended at roomtemperature:

Blend of- Grams 1320 gm. Hycar 1001 2 440 gm. polyester resin (55/45terephthalic acid/isophthalic acid condensed with ethylene glycol) 308gm. P,P'-oxybis (benzenesulfonyl hydra- Zide) 100 gm. carbon black 17gm. dicumyl peroxide 17 gm. Neozone D rubber antioxidant Pyromelliticdianhydride 0.9 N,N'-bis-ethylene isosebacamide 2.0

Butadieneacrylonitrile rubber, sp. gr. 1.00, Mooney Viscosity range-115, contains octylated diphenylamines as antioxidant.

The admixture was heated under an infra-red lamp to produce a somewhatbrittle foamed plastic which displayed excellent adhesion to aluminum.

7 Example 2 108 parts by weight of N,N'-bis-ethylene sebacamide wasmelted and admixed with 54.4 parts by weight (1/1 equivalent ratio) ofpyromellitic dianhydride and the ad mixture was spread onto glass cloth,from which a 12 ply 5 inch by 5 inch laminate was prepared. The laminatewas cured for 20 minutes at 310 F. (25 p.s.i.) in a heated hydraulicpress and then cured for 14 hours at 350 F. in an oven. The cured glasscloth laminate dis played good adhesion properties and was resistant todelamination.

Example 3 To illustrate the use of these liquid compositions as castingresins, the following three anhydrous specimens were admixed and curedin aluminum dishes (cure sequency16 hours at 60 C., 4 hours at 80 C., 12hours at 120 C. and 16 hours at 177 C.).

Parts by weight Specime n A B C Chlorendic anhydride 98 98 114 N,N-bis-ethylene isosebacamide... a 100 N,N-bis-ethylene sebacamide 100N,N-bis-ethylene isophthalamide 100 All three specimens were gelledafter 16 hours at 60 C. The cured copolymers of specimens A and B werereddish in color, and the cured copolymer of C was gray.

Example 4 The following anhydrous specimens were admixed and cured inaluminum dishes (16 hours at 60 C., 4 hours at 80 C., 16 hours at 120C., and 16 hours at 177 C.).

Parts by weight Specimen A B Methyl nadic anhydride 47 47 55N,N-bis-ctl1ylene isosobacarnide, 100 N,N-bis-ethyleue sebacamido 100 N,N -l)isethyleno isophthalamidc 100 All three specimens gelled after 16hours at 60 C., were reddish in color, and changed to black in the 120C.

The following specimens were admixed and cured in aluminum dishes (16hours at 60 C., 4 hours at 80 C., 16 hours at 120 C., 16 hours at 350F.).

Parts by weight Specimen A B C Pyrornellitic dianhydride 29 29N,N-bis-ethylene isosebacamido. 100 N,N-bis-cthylene scbacarnide. 100 N,N-bis-ethylcno isophthalamide 100 Specimens A and B were black incolor. Specimen C was green colored. Specimens A and C Were hardresinous copolymers after 16 hours at 60 C.

Similar results can be obtained by admixing other alkyleniminederivatives described earlier and other anhydrides set forth earlier,and curing the anhydrous admixture at elevated temperatures, theconditions and temperatures being selected to provide a homogeneousadmixture at the cure temperature.

The anhydrous stable compositions of this invention can also be cured inthe presence of moisture either at room temperature or at slightlyelevated temperatures to provide a hard resinous polymer with an unusualcombination of properties, including prolonged shelf life, long pot lifeat elevated temperatures, and excellent bonding or adhesivecharacteristics. In such cases, the admixture should be homogeneous atroom temperature. When these compositions are used as adhesives andcements they may be applied directly to the appropriate surfaces andcured by contact with water. Since water serves as activating agent, thesurfaces may be wetted prior to application of the adhesive or cement.In fact, it is one of the advantages of these compositions that thesurfaces to be bonded or laminated need not be dry, this being anoutstanding property when such compositions are used as dental cementsor filling compounds. Contact with moist air will also effect a cure,though at a relatively slow rate. In certain instances the water ofactivation can be incorporated into the composition in the form of ahydrate which loses water at temperatures above room temperature.Illustrative of such a hydrate is sodium borate decahydrate, which loseswater at elevated temperatures of about 168 F. Particularly whenlaminating low heat conductive materials, e.g. wood, the heat liberatedby the exothermic reaction is sufficient to liberate water of hydrationfrom the added hydrate and thereby to make the curing reactionself-propagating. In the more usual application however, the anhydrideand alkylenimine derivatives are admixed with an approximatestoichiometric amount of water immediately prior to use. This amount ofwater used may vary widely from the preferred approximate stoichiometricamount required to convert the anhydride to the corresponding acid, e.g.as low as about 20% of the stoichiometric amount, but excess water, e.g.more than 50% excess over the stoichiometric amount, is usuallyunnecessary. Any exothermic reaction, of course, may result in the lossof water and appropriate compensation may be made for this loss. Withthe lesser amounts of water, the rate of reaction is correspondinglylower, and the ultimate cure may be limited by the available moisture inthe environment.

The copolymers produced by curing the stable anhydrous admixtures ofthis invention in the presence of water are distinct from those producedby heating the anhydrous mixture to an elevated temperature withoutwater contact. The mechanism appears to involve the hydrolysis of theacid anhydride to the corresponding acid and the reaction of this acidwith the alkylenimine derivative by opening the azirane ring andaddition of the active hydrogen from the carboxyl group to the nitrogenatom. These water cured products provide a one-part adhesive compositionwhich can readily be cured with negligible shrinkage to form a tough,water-resistant bond between various materials such as wood (e.g. marineplywood), stone, synthetic resins and elastomers, bone, metals (e.g.aluminum, etc), glass, synthetic and natural fibers, etc.

The following examples are presented for purposes of illustrating thecuring in the presence of water and are not necessarily to be construedas limiting the scope of the invention. All cures are elfected at roomtem perature unless otherwise indicated.

Example 6 Two grams of N,N-bis-ethylene isosebacamide were mixed withone gram of pyromellitic dianhydride. Two pieces of plywood were soakedin water for several minutes and were coated with this mixture. Anoverlap bond of one square inch contact surface was clamped intoposition with a C-clamp. After ten minutes the specimen was tested onthe Instron Tensile Test machine, and a force of 225 pounds per squareinch was required to cause rupture. Failure resulted from completedelamination of plywood, the adhesive line remaining intact.

Following a similar procedure the following specimens were prepared andtested:

TABLE I Example N 7 8 9 10 11 12 Pyromellitic dianhydride 3 2. 5 2 4 N,N-bis-ethylene isosebacamide. 6.0 6 4 6 3 Poly Bd PMDA 1.0 2 1 1Chlorendic anhyd 0 7. 5 3 Tensile, p.s.i.:

Dry 460 360 225 180 260 Wet 90 G5 50 Failure:

Dry W WA A A A et A A A A A Example No 13 14 l 15 16 17 18 Pyromelliticdianhydride Poly Bd-crloro maleic 2 N,N-bis-ethylene isosebacamideChlorendic anhydride. Dodecyl suecinic anhydride. N ,N -bis-ethylenesebacamide Vinyl butyl ether-maleic anhydride 3 Bentone 34 Cabosil 2.0

Example No 13 14 15 16 17 18 NazB4O7-10H2O 3. 0 Tensile, p.s.i.:

D 665 220 785 820 435 600 et 50 280 315 350 250 290 Dry W A W W WA W WetA W WA WA WA WA Liquid copolymer of butadiene and styrene (85:15 11101ratio), +20 weight percent pyromellitic dianhydride.

2 Liquid copolymer of butadiene and styrene (85:15 mol ratio), +20weight percent chloromaleic anhydride.

3 Robbery polymer of vinyl normal butyl ether and maleie anhydideprepared by reacting 2 parts of ether and approximately 2 parts of anhydlidf in the presence 01 01-1 012 and azobisisobutyronitrile (18 hoursat 4 Bentone 34 is finely divided dimethyldiooctadecyl ammoniumbentonite (National Lead 00.).

5 Cabosil is colloidal silica prepared in a hot Iaseous environment byvapor-phase hydrolysis of a silicon compound (Godfrey L. Cabot, 1110.).Failure: W=wood; A=adhesive.

The preparation of Example 18 illustrates a unique method forincorporating water of actlvation into the recipe. A hydrate, such asborax decahydrate, is milled into the system. At a temperature of about168 F, sodium borate decahydrate loses eight molecules of water, whichthen activates the anhydride an it polymerization with the alkyleniminederivative. Such an adhesive, when placed in a dry wood glue line, canbe activated by heating one point or edge of the glue line to atemperature above the dehydration temperature. With low heat conductivematerials, such as wood, the highly exothermic reaction can beself-propagating through the glue line.

Example 1 9 A concrete block was coated with a composition having thefollowing ingredients:

Parts by weight N,N'-bisethylene isosebacamide 4 N,N'-bis-ethylenesebacamide 2 Pyromellitic dianhydride 1 Dodecyl succinic anhydride 1 Thecoated block was placed in water with the coated surface above the waterline. After 24 days no detrimental effects on the coating were observed,and the coating could not be removed from the concrete surface.

To illustrate the cured systems of this invention with regard to boththe rate and the extent of reaction representative runs are set forth inTable II. For purposes of comparison, the extent of reaction was assumedto be represented by the water sensitivity of the cured system. This wasdetermined by hydrolyzing the cured system for 7 days at F. andtitrating the water phase, the resulting acid value indicating theamount of car boxyl groups freed during hydrolysis. However, the residuematerial also contained carboxy groups that were not water soluble. Whenthis residue was placed into solution in alcohol, further titrationindicated the amount of carboxy groups freed from the residue. Theoverall extent of reaction was calculated from the combined acid numberof the water phase and the residue.

TABLE II Reaction product data of N,N'-bis-ethylene isosebacamide andanhydride Equivalent Reaction ratio of Extent of time Anhydridealkylenimine reaction, (room derivative percent temp.) anhydride daysMethyl maleic 1/1 71. 2 1-2 Methyl maleic 1. 3/1 76.. 0 1-2 Methylsuccinic. 1. 3/1 81.. 1 2-3 03 alkyl succinic 1. 3/1 88. 3 2-3 C12 alkylsuccinic- 1/1 76. 3 3 Clilalky1Sl1CCilllC/ 1.3/1 90.0 3 26 Methylnadic1.3/1 93.2 5 27..-. Tetrahydro- 1/1 2 phthalic. 28 Benzoic 1/1 a- 6Other alkylenimine derivatives were also evaluated in terms of reactiontime, i.e. time required for the formation of a tack-free cured product.Table III illustrates the reaction of trls-azlndyl phosphine oxide andvanous anhydrides.

TABLE III Reaction product data of tris aziridyl phosphine oxide andanhydride Equivalent Wt. percent ratio of 11 0 (based Reaction ExAnhydride alkylenimine on reactive Time derivative/ ingredients)(minutes) anhydride 29".- Chloromaleic 1/1 0 0.28 30 Dodecenyl succinic0.75/1 0 10 31 Maleic 1/1 0 5 32 Methylnad 0.75/1 0 10 33 chloromaleic1/1 0 1 hydride-pentaerythritol adduct. 34 Chloromaleic 1/1 10 0.11 35chloromaleic 1/1 24 0. 09 36.." Dodecenyl succ 1/1 24 37.--. Maleic 1/124 2.40

1/1 24 1/1 24 40...- Pyroinellitie dian- 1/1 24 0.55

hydride. 41-. Trimellitic 1/1 24 0.63 42 Dirnethyl butenyl 1/1 10tetrahydrophthallic.

3 hours. 2 4 hours.

Table IV illustrates the use of chloromaleic anhydride with variousalkylenimines and mixtures thereof, including the use of added fillerssuch as titanium dioxide. All systems were evaluated on a basis of 1/ 1ratio of reactive azirane ring equivalents to acid equivalents. Ratiosin parentheses are by weight.

TABLE IV Reaction product data of chloromaleic anhydride andalkylenimine derivative Reaction Ex. Alkylenimine derivative time.

minutes 43 Tris-aziridyl phosphine oxide; N,N-bis-ethylone 3.0

isosebacamide (3:7).

44 Tris-aziridyl phosphine oxide 1.0

45 Tris-aziridyl phosphine oxide: N,N-bis-etl1ylene 1.4

isosebacamide (8:2).

46 Tris-aziridyl phosphine oxide: N,N-bis-ethylene 2.0

isosebacamide (6:4).

47 Tris-aziridyl phosphine oxide: N,N-bis-ethylene 3.0

isosebacamide (4:6).

48 Tris-aziridyl phosphine oxide: N,N-bis-ethylene 4.0

isosebacamide (2:8).

49 N,N-bis-etl1ylcne isosebacamide 20.0

50 Tris-aziridyl phosphine oxide: N,N-bis-ethylene 1.8

sebacamide (8:2).

51 Trisazi idyl phosphine oxide: N,N-bis-ethylene 2.5

sebacamide (6:4

52 Tris-aziridyl phosphine oxide: N,N-bis-ethylene 3.0

sebacamide (4:6).

53 Tris-aziridyl phosphine oxide: titanium dioxide 0.8

54 Tris-aziridyl phosphine oxide: N,N-bis-ethylene 1.5

isosebaeamide: titanium dioxide (4:1:5).

55 Tris-aziridyl phosphine oxide: N,N-bis-ethylene 2.5

sebacamide: titanium dioxide (4:1:5).

Specimen 1 2 3 4 Wt percent acrylate adhesive 100 80 60 Wt perce nt anhydride adhesive 0 20 40 60 Shear tensile, p.s.i 140 400 515 510Failure 1 Adhesive. 2 Cohesive and adhesive. 3 Tooth broke.

The data in Table V indicates the relative effect on reaction time (i.e.time taken for a one gram sample to become tack-free or to completereaction, average of three or more samples) of varying ratios ofalkylenimine ring acid equivalent.

TABLE V Run A B C D E F G H Wt., gram tris-aziridyl phosphine oxide"0.30 0.40 0. 0. 54 0. 0.70 0.75 0.80 Wt., gram, ehloromaleic anhydride0.70 0.60 0. 50 0. 46 0.40 0. 30 0. 25 0. 20 Imine ring equivalent 0.0039 0. 0052 0. 0065 0. 0070 0. 0078 0. 0091 0. 0098 0. 0104 Acidequivalent 0. 0106 0. 0001 0. 0076 0. 0070 0. 0061 0. 0045 0. 0038 0.0030 Imine ring/acid equivalent 0.37 0. 57 0.86 1.0 1. 3 2.0 2. 6 3. 5Average reaction time, minutes 4. 00 1. 00 0.34 0.28 0.34 0. 43 0. 490.86

Although, as mentioned earlier, various hydroxy containing initiators,including water, alcohols, etc., can be used to activate the reaction ofalkylenimine derivative and anhydride, water is most effective, since itproduces the acid from the anhydride. Alcohols form partial esters withanhydrides, thus reducing the amount of acid present and causing chaintermination.

Example 56 The outstanding ability of these curable compositions toadhere to bone has been demonstrated.

A 2/1 weight ratio of pyromellitic dianhydride and dodecenyl succinicanhydride was dispersed in three passes on a paint mill. A second blendof N,N-ethylene isosebacamide and N,N-bis-ethylene sebacamide (6/4weight ratio) was also dispersed by the same technique. Then one part ofthe anhydride blend was added to 1.2 parts by weight of the alkyleniminederivative blend, with the addition of water in the amount of 5% byweight of the latter. After thorough mixing a hard cured resin wasobtained after about 5 minutes.

The above liquid adhesive was successfully used to bond polymethylmethacrylate electrode buttons to the skulls of living rats for brainreaction research. The bone to which the liquid is applied was spongedto remove excess fluid, avoiding complete dryness which would hinder thereaction.

Example 57 The curable compositions of this invention has also beenfound to possess the properties of adhesion and dimensional stabilitynecessary for dental resins and adhesives.

In addition to the uses set forth earlier, these liquid curablecompositions can also be employed as impregnating agents for paper,synthetic and natural fibers and textiles, etc. For impregnating themore dense materials and for improving the compatibility of theingredients, organic solvents, such as ethyl cellosolve, methyl ethylketone, butyl acetate, etc., can be included in the anhydrous systems tolower the viscosity or flowability, permit easier penetration of thematrix, and to increase the cure rate. Such thinners and diluents alsofacilitate coating operations, such as spraying, etc.

Various modifications and alterations in the curable compositions andutility thereof will become apparent to those skilled in the art withoutdeparting from the scope of this invention.

I claim:

1. An essentially anhydrous, active hydrogen free, room temperaturestable admixture consisting essentially of an organic acid anhydride ofa polycarboxylic acid as one reactant and, as the other reactant, fromabout stoichiometric amount to about 50% excess of an azirane ringcontaining compound selected from the group consisting of:

(1) a phosphine oxide having, as the sole groups capable of reactingwith anhydride, from 2 to 3 radicals of the formula CRIB/I (3) anorganic compound containing, as the sole groups capable of reacting withanhydride, from 2 to 3 radicals of the formula CH2 ll wherein Y isselected from the group consisting of NH .and oxygen, x is either 0 or1, and R and R" are selected from the group consisting of hydrogen and alower alkyl radical having from 1 to 8 carbon atoms each of saidreactants being free of substituents which cause opening of aziranerings at room temperature, said admixture being curable and homogeneousat an elevated temperature below the boiling point of each of theaforesaid compounds.

2. An essentially anhydrous, active hydrogen free, room temperaturestable admixture consisting essentially of an organic acid anhydride ofa polycarboxylic acid as one reactant and, as the other reactant, fromabout stoichiometric amount to about 50% excess of a phosphine oxidehaving from 2 to 3 radicals of the formula CRR wherein R and R areselected from the group consisting of hydrogen and a lower alkyl radicalhaving from 1 to 8 carbon atoms, each of said reactants being free ofsubstituents which cause opening of azirane rings at room temperature,said admixture being curable and homogeneous at an elevated temperaturebelow the boiling point of each of the aforesaid compounds.

3. An essentially anhydrous, active hydrogen free, room temperaturestable admixture consisting essentially of an organic acid anhydride ofa polycarboxylic acid as one reactant and, as the other reactant, fromabout stoichiometric amount to about 50% excess of a phosphine sulfidehaving from 2 to 3 radicals of the formula CRIRIV wherein R and R" areselected from the group consisting of hydrogen and a lower alkyl radicalhaving from 1 to 8 carbon atoms, each of said reactants being free ofsubstituents which cause opening of azirane rings at room temperature,said admixture being curable and homogeneous at an elevated temperaturebelow the boiling point of each of the aforesaid compounds.

4. An essentially anhydrous, active hydrogen free, room temperaturestable admixture consisting essentially of an organic acid anhydride ofa polycarboxylic acid as one reactant and, as the other reactant, fromabout stoichiometric amount to about 50% excess of an organic compoundcontaining, as the only groups capable of reacting with anhydride at anelevated temperature, from 2 to 3 radicals of the formula wherein Y isselected from the group consisting of NH- and oxygen, x is either 0 or1, and R and R" are selected from the group consisting of hydrogen and alower alkyl radical having from 1 to 8 carbon atoms, each of saidreactants being free of substituents which cause opening of aziranerings at room temperature, said admixture being curable and homogeneousat an elevated temperature below the boiling point of each of theaforesaid compounds.

5. An essentially anhydrous, active hydrogen free, room temperaturestable admixture consisting essentially of an organic acid anhydride ofa polycarboxylic acid as one reactant and, as the other reactant, fromabout stoichiometric amount to about 50% excess of a compound of theformula wherein Y is selected from the group consisting of NH andoxygen, x is either 0 or 1, R and R" are selected from the groupconsisting of hydrogen and a lower alkyl radical having from 1 to 8carbon atoms, and R has from about 4 to about 40 carbon atoms and isselected from the group consisting of a divalent aliphatic, a divalentaromatic and a divalent alicyclic radical, each of said reactants beingfree of substituents which cause opening of azirane rings at roomtemperature, said admixture being curable and homogeneous at an elevatedtemperature below the boiling point of each of the aforementionedcompounds.

6. The admixture of claim 5 in which the admixture is essentiallyhomogeneous at room temperature.

7. The admixture of claim 5 in which the compound of the recited formulais N,N'-bis-ethy1ene isosebacamide.

8. The admixture of claim 5 in which the compound of the recited formulais N,N-bis-ethylene sebacamide.

9. The admixture of claim 5 in which the compound of the recited formulais N,N-bis-ethylene isophthalamide.

10. The admixture of claim 2 in which said phosphine oxide istris-aziridyl phosphine oxide.

11. The admixture of claim 3 in which said phosphine sulfide istris-aziridyl phosphine sulfide.

12. An essentially anhydrous, active hydrogen free, room temperaturestable admixture consisting essentially of pyromellitic dianhydride andfrom about stoichiometric amount to about 50% excess of N,N-bis-ethylenesebacamide.

13. An essentially anhydrous, active hydrogen free, room temperaturestable admixture consisting essentially of methyl nadic anhydride andfrom about stoichiometric amount to about 50% excess of tris-aziridylphosphine oxide.

14. A curing process which com-prises heating to an elevated temperaturean essentially anhydrous, active hydrogen free, room temperature stableadmixture consisting essentially of an organic acid anhydride of apolycarboxylic acid as one reactant and, as the other reactant, fromabout stoichiometric amount to about 50% excess of a phosphine oxidehaving from 2 to 3 radicals of the formula CRIRI! wherein R and R" areselected from the group consisting of h drogen and a lower alkyl radicalhaving from 1 to 8 carbon atoms, each of said reactants being free ofsubstituents which cause opening of azirane rings at room temperature,said admixture being curable and homogeneous at an elevated temperaturebelow the boiling point of each of the aforesaid compounds.

15. A curing process which comprises heating to an elevated temperaturean essentially anhydrous, active hydrogen free, room temperature stableadmixture consisting essentially of an organic acid anhydride of apolycarboxylic acid as one reactant and, as the other reactant, fromabout stoichiometric amount to about 50% excess of a phosphine sulfidehaving from 2 to 3 radicals of the formula wherein R and R are selectedfrom the group consisting of hydrogen and a lower alkyl radical havingfrom 1 to 8 carbon atoms, each of said reactants being free ofsubstituents which cause opening of azirane rings at room temperature,said admixture being curable and homogeneous at an elevated temperaturebelow the boiling point of each of the aforesaid compounds.

16. A curing process which comprises heating to an elevated temperaturean essentially anhydrous, active hydrogen free, room temperature stableadmixture consisting essentially of an organic acid anhydride of apolycarboxylic acid as one reactant and, as the other reactant, fromabout stoichiometric amount t about 50% excess of an organic compoundcontaining, as the only groups capable of reacting with anhydride at anelevated temperature, from 2 to 3 radicals of the formula wherein Y isselected from the group consisting of References Cited by the ExaminerUNITED STATES PATENTS 2,l30,948 9/1938 Carothers 260-78 2,915,48012/1959 Reeves et a1. 26078.4 3,115,474 12/1963 Smith 26078 3,115,48212/1963 Smith 26078 WILLIAM H. SHORT, Primary Examiner.

LOUISE P. QUAST, Examiner.

H. D. ANDERSON, Assistant Examiner.

1. AN ESSENTIALLY ANHYDROUS, ACTIVE HYDROGEN FREE, ROOM TEMPERATURESTABLE ADMIXTURE CONSISTING ESSENTIALLY OF AN ORGANIC ACID ANHYDRIDE OFA POLYCARBOXYLIC ACID AS ONE REACTANT AND, AS THE OTHER REACTANT, FROMABOUT STOICHIOMETRIC AMOUNT TO ABOUT 50% EXCESS OF AN AZIRANE RINGCONTAINING COMPOUND SELECTED FROM THE GROUP CONSISTING OF: (1) APHOSPHINE OXIDE HAVING, AS THE SOLE GROUPS CAPABLE OF REACTING WITHANHYDRIDE, FROM 2 TO 3 RADICALS OF THE FORMULA (2) A PHOSPHINE SULFIDEHAVING, AS THE SOLE GROUP CAPABLE OF REACTING WITH ANHYDRIDE, FROM 2 TO3 RADICALS OF THE FORMULA